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K Soda

Publications and source records attributed to K Soda.

At least 361 records · Page 20Linked to original sources

Occurrence of taurine: -ketoglutarate aminotransferase in bacterial extracts.

High activity of taurine:alpha-ketoglutarate aminotransferase was found exclusively in cell-free extracts of Achromobacter superficialis and A. polymorph. The former was chosen for characterization of the enzymatic reaction. The enzyme activity was enhanced by addition of beta-alanine to the growth medium. The product from alpha-ketoglutarate was identified as l-glutamate. Another product has been isolated, purified, and identified as sulfoacetaldehyde (2-oxoethanesulfonate), a deamination product from taurine, by comparison between the 2,4-dinitrophenylhydrazones of the synthetic and enzymatic products on the basis of studies by paper chromatography, by visible, infrared, and nuclear magnetic resonance spectrophotometries, and by elemental analysis. This enzymatic transamination was found to proceed stoichiometrically and reversibly as follows: NH(2).CH(2).CH(2).SO(3)H + HOOC.CH(2).CH(2).CO.COOH right harpoon over left harpoon OHC.CH(2).SO(3)H + HOOC.CH(2).CH(2).CH(NH(2)).COOH.

Alanine↗

Spectrophotometric determination of pyridoxal and pyridoxal 5'-phosphate with 3-methyl-2-benzothiazolone hydrazone hydrochloride, and their selective assay.

A spectrophotometric method with 3-methyl-2-benzothiazolone hydrazone hydrochloride was developed for the determination of pyridoxal and pyridoxal 5'-phosphate, and for the selective determination of each in the presence of the other. Pyridoxal and pyridoxal 5'-phosphate react with the reagent to yield the azine derivatives, which give characteristic absorption spectra. The highest extinction values are obtained when pyridoxal and pyridoxal 5'-phosphate are incubated at pH values of about 3.4 and 8.0 respectively; their maxima are at 430nm. (in 2.74x10(4)) and 380nm. (in 2.24x10(4)) respectively. The azine of pyridoxal is only slightly soluble under the neutral and alkaline conditions, whereas that of pyridoxal 5'-phosphate is substantially insoluble in the acid pH range. This difference in solubility of the azines made possible the selective determination of pyridoxal and pyridoxal 5'-phosphate. alpha-Oxoglutarate and pyruvate are among the substances shown not to interfere with the assay of pyridoxal; their derivatives absorb appreciably only at wavelengths below 420nm. For the assay of pyridoxal 5'-phosphate in the presence of these compounds measurement at 390nm. is necessary.

Azides↗